The efficiency of compact gas turbine engines has been demonstrated in non-military vehicular applications involving automobiles, buses, and trucks. Companies such as Ford, General Motors, Chrysler, BMW, Mercedes Benz, Rover, Garret and others have built and tested them. However, because of cost of the gas turbine and the associated installation costs, no one has been able to place them in large scale commercial automotive production. Only the military has been able to afford such engine systems to date.
Electric vehicles are now being mandated by law. In 1998, 2% of all vehicles delivered in the State of California by manufacturers selling more than 35,000 vehicles per year must have "zero" pollutant emissions. In the years 2001 and 2003, the zero emission requirement increases to 5 and 10%, respectively. These "zero" emission vehicles are presumed to be electrically powered, since power from batteries does not produce NOx, CO or hydrocarbons emissions.
The problem with the electric vehicle is that it does not have adequate range when powered by batteries that are currently available. As the re-charge time requires several hours, electric vehicles are impractical for extended distance driving. If air conditioning or heating is needed the range can be further reduced by up to a third or more. Accordingly, the hybrid electric vehicle, using an auxiliary power unit, in the form of a small gas turbine generator set, may be used as a second source of electrical energy in association with the battery.
In the most basic version of this type of hybrid electric vehicle, the small gas turbine generator set is a range extender. The vehicle uses the batteries to provide electricity for normal driving. On days when the vehicle is only driven for short distances, such as back and forth to work or on shopping expeditions, the small gas turbine would not be started. However, when the battery is discharged to some pre-determined limit, the gas turbine generator set would start and extend the range. Indeed, if the gas turbine generator set has adequate power, the range can equal that of a conventional vehicle even if air conditioning or heating is needed.
However, the majority of small gas turbine engines utilize a design approach that is inherently expensive. Virtually all gas turbine engines that have actually been demonstrated on the road use free turbine drives and multi-speed reduction gear boxes with reverse capabilities to transmit power. Virtually all of them have secondary auxiliary gear boxes for a wide variety of engine driven accessories. All have complete and complex lubrication systems with pumps, oil coolers, sumps, etc. All have complex control systems to govern the speeds of two separate rotors and allow maximum gas producer rotor acceleration without overheating. Many incorporate variable geometries in the compressor diffusers or the turbine nozzles to improve response time and to enhance part load performance. Some use power transfer clutches. Gas turbine engines for automotive applications have used rotary regenerators to improve the engine efficiency. These regenerators are very expensive and have an inherent problem with seal leakage.
Thus, there is a need for a power source using a small gas turbine engine. Also for a power source which has no gear box, no lubrication system, no liquid coolants and no engine driven accessories. Additionally, there is a need for a power source which is affordable, compact, and provides a light weight power package with low emissions that can be used to generate electricity and to extend the range of electric vehicles to equal or exceed those of conventional cars, trucks and buses.
The subject invention herein solves all of these problems in a new and unique manner at economically affordable costs. Some related patents directed to gas turbine engines and recuperators are described below:
U.S. Pat. No. 5,082,050 issued to C. T. Darragh on Jan. 21, 1992
This patent discloses a circular heat exchanger designed to increase the efficiency of an engine by utilizing the heat from the exhaust gas to pre-heat the intake air. The circular heat exchanger comprises a plurality of evenly spaced individual tension rings which are positioned about the outer portion of the core of the heat exchanger, and a plurality of compressive hoops which as positioned at the inner portion of the core, thereby resisting the forces which are attempting to separate the heat exchanger passages. The rings and the hoops are in contact with the core providing heat transferring relationship with the donor fluid. The rings further expand and contract in response to the temperature changes of the donor fluid, and maintain a pre-established force on the core of the heat exchanger.
U.S. Pat. No. 4,993,223 issued to K. Kretzinger on Feb. 19, 1991
This patent describes a circumferential recuperator for use with a turbine engine. The circumferential recuperator is constructed from a plurality of stacked formed plates, alternately sandwiching radially aligned exhaust passageways, with partially circumferentially aligned air passageways, in heat exchange relationship. The air passageways further contain generally Z-shaped fin passageways inter-connecting actually aligned inlet and outlet manifolds within the annular core of the recuperator.
U.S. Pat. No. 4,470,453 issued to R Laughlin, et al Sep. 11, 1984
This patent describes a heat exchange apparatus having a plurality of plates through which heat is exchanged from a first gas to a second gas, and is provided with a plurality of plates having first and second opposing patterns. Each of the opposing patterns is provided with a plurality of sinusoidally varying surface strips, whereby the second gas flows in a generally sinusoidal path in a first direction along a first side of the first and second patterns between the first and second plates and the first gas flows in a generally sinusoidal path in a direction opposite the first direction along the other side of the first and second plates. The first and second patterns are provided with sealing ridges in abutting relationship, the sealing ridges so disposed to provide an inlet and outlet for the second gas when the plates are mounted in the heat exchange apparatus.
U.S. Pat. No. 2,368,732 issued to A. G. Wallgren on Feb. 6, 1945
This patent describes a water cooler for use in connection with internal combustion engines, and is designed to carry off large quantities of heat energy, while being compact in size. The water cooler comprises a ring of stationary guide blades provided to impart the desired direction of the flow of the air. Additionally, the design includes a series of metal plates disposed in planes at right angles to the motor shaft and the fan shaft, formed into passageways to allow the cooling air and hot liquid from the motor in heat exchange relationship.
U.S. Pat. No. 2,939,686 issued to J. Wildermuth on Jun. 7, 1960
This patent describes a heat exchange surface comprising respective plates with substantially hemispheric knobs, which serve the purpose of providing a flow disturbing surface across which the liquid to be cooled must flow, and spacing the plates apart. The knobs are arranged in a symmetrical pattern but are sufficiently off center so that when these alternate plates are inverted, the knobs of one plate bear against an unembossed portion of the next adjoining plate. Each plate is provided with a plurality of gasket grooves, there being lengthwise grooves along each side of the heat exchange area containing the knobs. The above described heat exchanger is primarily used for cooling milk, by the use of cold well water as it passes through the above described plates.